Kidney Cancer

Kidney cancer is the cancer of the kidneys, 2 bean-shaped organs responsible for the removal of waste from our body into the urine. Kidney cancer is among the top 10 most common cancers affecting men in Singapore.

Kidney cancer is a silent killer. By the time that symptoms are noticeable, the cancer is usually in the late stage. It is very important that symptoms are taken seriously when they occur, as further delay in treatment will delay its effectiveness.

Causes of Kidney Cancer

The causes of kidney cancer remain an enigma. Certain hereditary conditions predispose an individual to kidney cancer but these familial cancer lineages are uncommon. Cigarette smoking increases kidney cancer risks by multiple fold and long-term use of certain painkillers has also been implicated. Poorly controlled hypertension also seems to have an association but the causative effect of this has never been unequivocally proven.

Although the incidence of kidney cancer locally has remained stable in the past decade, there is an increase in the number of early kidney cancers treated. These are usually picked up during health screening when small kidney masses, which otherwise have no overt clinical symptoms, are identified. These patients are usually healthy individuals.

The symptoms of kidney cancer are blood in the urine, flank pain and palpable mass, but the reality is that by the time these symptoms occur, the disease is usually in the late stages.

Early kidney cancer usually has no symptoms. Late kidney cancer can present with flank mass and pain, blood in the urine, loss of weight and appetite, abdominal bloating, anaemia and palpitations. It can spread to other organs including the lungs, liver and bones causing pain and other systemic derangements.

If you experience blood in your urine, a urine test can help detect urinary tract diseases, stones, infections or cancers. If you are suspected of having kidney cancer, your doctor may refer you for more in-depth tests.

Blood in the urine not visible to the naked eye but only detected through urine analysis (microscopic haematuria) remains the most common symptom of early kidney cancer. Most patients with early stage kidney cancer discover this symptom through routine health checks. Patients with microscopic haematuria but having no other symptoms should undergo tests to discover its cause. Depending on the individual’s risk factors, blood in the urine can be evaluated with tests such as an ultrasound or CT scan.

Imaging tests such as ultrasounds, computerised tomography (CT) scans or magnetic resonance imaging (MRI) scans can provide a comprehensive image of your kidney and any growths that it may have. Sometimes, a growth that is seen during imaging tests may be benign and not cancerous.

Treatment and prognosis of early versus late kidney cancers differ vastly.

Small kidney cancers found incidentally during routine health checks have a high cure rate and chemotherapy and radiotherapy are rarely necessary. Kidney cancers in their late stages, however, may carry a much poorer outcome and its management tends to be centred on palliative measures.

Systemic treatment of kidney cancer

Chemotherapy has little role in kidney cancers. Other systemic treatments likely multi-kinase inhibitors can play a role in managing late-stage kidney disease. Radiotherapy has a role in the local control of kidney cancer spread. In patients with terminal kidney cancer that has spread to the spine or bones, local radiotherapy can reduce the risk of spinal cord compression and pathological fractures caused by cancer destroying the bones.

Removing small tumours

In carefully selected patients, small renal masses can be removed with techniques such radiofrequency ablation (RFA) and cryoablation. These options use heat and cold respectively to kill cancerous cells while preserving the remaining kidney tissue. When used in carefully selected patients, this can attain good long-term cure rates.

Advanced techniques to treat early kidney cancers

Minimally invasive (MIS) partial nephrectomy has revolutionised the way we manage small, early kidney cancers. Traditionally, patients with kidney cancer will have their affected kidney removed through surgery. In MIS partial nephrectomy, the affected kidney is spared with the surgeon removing only the tumour. This procedure can help preserve kidney tissue and reduce the chance of patients with pre-existing kidney failure needing kidney dialysis.

MIS partial nephrectomy typically involves a short hospital stay and reduced post-operative pain as surgical wounds are much smaller than traditional open surgery. Post-operative recovery tends to be faster than traditional open surgery with the patient getting back to normal activities quicker.

Studies have shown that there is no difference in cure rates between MIS partial nephrectomy and radical nephrectomy, in which the entire kidney is removed.

Prevention of kidney cancer

As the causes of kidney cancer remain a mystery, there are no definitive ways to prevent it. Maintaining good control of blood pressure and quitting smoking can help reduce the risk of kidney cancer. A balanced diet, regular exercise and adequate sleep are also steps which can potentially help reduce the risk of major cancers.